Authorityspoke

------------------
* remove Enactment download functions (use Legislice download client instead)
* remove Opinion download functions (use CAPClient class instead)
* use different Legislice schema imports for JSON and YAML
* move fake download client to separate module
* add read methods to CAP opinion download client
* add read methods to CAPClient
* DecisionSchema can accept months instead of dates
* merge CAPCitation and CAPCitationTo schemas
* Holding has separate add_enactment and with_enactment methods
* Rule has separate add_enactment and with_enactment methods
* Rule has separate add_factor and with_factor methods
* Procedure has separate add_factor and with_factor methods
* increase versions of Nettlesome and Legislice dependencies
* add CAPClient to top level of package
* add "Creating and Loading Holding Data" documentation page
* Rules select all text of Enactments without selected text only during init, not during schema load
* change field name from "quotes" to "anchors" in YAML import files
* fix bug: dump methods couldn't find Decision and Opinion schemas

------------------
* Comparison methods use Explanations instead of ContextRegisters
* Remove io/anchors module
* Remove "factors" module that conflicted with Nettlesome module of same name
* Add Fact.negated method
* Remove "role" param for Procedure.add_factor
* Rules can be added even if one of the operands has more Enactments
* Procedure.recursive_terms doesn't include FactorGroups
* Procedure.terms doesn't include FactorGroups
* Add comparable_with methods
* Decision is no longer a dataclass
* remove context param from Opinion comparisons
* handle Opinion.explanations_implication(HoldingGroup)
* Increase minimum Nettlesome version to 0.5.0

------------------
* Import Nettlesome library as dependency
* Remove "anchors" fields from Factors in AuthoritySpoke Holding API Schema

------------------
* Predicate.content attribute no longer includes an extra placeholder for a "quantity"
* Predicate.content attribute must be a valid Python string template
* Rename "context_factors" field to "terms"
* Rely on Predicate placeholder names to label terms as interchangeable
* Remove Predicate.reciprocal field used to label terms as interchangeable
* Add Comparable class for Predicate with a numeric comparison
* Rename Comparable.quantity to Comparable.expression
* Comparable.expression can be a datetime.date

------------------
* Increase minimum Legislice version to 0.4.1
* Remove `read_enactments` and `read_enactment`. Use Legislice's download client or schema instead.

------------------
* Create `ComparableGroup` class for unordered `Factor` collections
* Create `FactorSequence` class for ordered `Factor` collections
* Eliminate Analogy class, moving its methods to `FactorGroup` and `FactorSequence`
* Add `Factor.consistent_with` method to search for available context avoiding contradiction
* Add "or" operator for `FactorGroup`
* Integrate Legislice API client for retrieving text from US Constitution and US Code
* Remove functions for loading legislation text from XML files. Use API client instead.
* Delete classes for accessing XML legislation files: `Code`, `Regime`, and `Jurisdiction`